IronPort Systems 4108GL User Manual

Page 340

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14-34

Port-Based Virtual LANs (VLANs) and GVRP
GVRP

Po

rt

-Ba

sed V

ir

tual

LANs

(VLAN

s) a

n

d

G

V

RP

Table 14-2. Options for Handling “Unknown VLAN” Advertisements:

The CLI

show gvrp command and the menu interface VLAN Support screen

show a switch’s current GVRP configuration, including the Unknown VLAN
settings.

Figure 14-22. Example of GVRP Unknown VLAN Settings

Unknown VLAN
Mode

Operation

Learn
(the Default)

Enables the port to dynamically join any VLAN for which it receives an
advertisement, and allows the port to advertise other other VLANs it knows.

Block

Prevents the port from dynamically joining a VLAN that is not statically
configured on that port. The port will still forward advertisements that were
received by the switch on other ports. Block should typically be used on
ports in unsecure networks, where there is exposure to “attacks”, such as
ports where intruders can connect.

Disable

Causes the port to ignore and drop all GVRP advertisements it receives and
also prevents the port from sending any GVRP advertisements.

GVRP Enabled

(Required for Unknown
VLAN operation.)

Unknown VLAN Settings

Default:

Learn

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